try yourself |run program

#include <stdio.h>
#include <conio.h>

void f1(){
 int a;
 printf("\n enter value for a: ");
 scanf("%d",&a);
if(a > 0){
 int m;
 printf("\n Enter value for m: ");
 scanf("%d",&m);
}
 printf("\n value of a = %d ",a);
 printf("\n value of m = %d ",m);
}

void main(){
 clrscr();
 f1();
 getch();
}

Program Output

Undefined symbol 'm'